The present invention relates generally to interface devices for allowing humans to interface with computer systems, and more particularly to computer interface devices that allow the user to provide input to computer systems and allow computer systems to provide haptic feedback to the user.
A user can interact with an environment displayed by a computer to perform functions and tasks on the computer. Common human-computer interface devices used for such interaction include a mouse, joystick, trackball, gamepad, steering wheel, stylus, tablet, pressure-sensitive sphere, or the like, that is connected to the computer system. Typically, the computer updates the environment in response to the user's manipulation of a physical manipulandum such as a joystick handle or mouse, and provides visual and audio feedback to the user utilizing the display screen and audio speakers. The computer senses the user's manipulation of the user manipulandum through sensors provided on the interface device that send locative signals to the computer. In some interface devices, kinesthetic force feedback or tactile feedback is also provided to the user, more generally known herein as “haptic feedback.” These types of interface devices can provide physical sensations which are felt by the user manipulating a user manipulandum of the interface device. One or more motors or other actuators are coupled to the housing or the manipulandum and are connected to the controlling computer system. The computer system controls output forces in conjunction and coordinated with displayed events and interactions by sending control signals or commands to the actuators.
Many low-cost haptic devices provide inertially-grounded tactile feedback, in which forces are transmitted with respect to an inertial mass and felt by the user, rather than kinesthetic feedback, in which forces are output directly in the degrees of freedom of motion of a moving manipulandum with respect to a physical (earth) ground. For example, many currently-available gamepad controllers include a spinning motor with an eccentric mass, which outputs force sensations to the housing of the controller in coordination with events occurring in a game. In some haptic mouse devices, pins, buttons, or the housing of the mouse can be actuated in accordance with interaction of a controlled cursor with other graphical objects, which the user feels by touching those housing areas.
One problem with such inexpensive haptic controllers is their limited ability to convey different types of force sensations to the user. A device that provides more flexibility for the developer in tuning and adjusting the feel of haptic sensations is more desirable. In addition, inertial controllers currently available can only provide output pulses and vibrations in the general directions of the rotating mass. The sensations thus feel to the user as if they are not output in any particular direction, but are simply output on the housing of the device. However, many events in games and other computer-implemented environments are direction-based and would benefit from a directionality to haptic sensations which current inertial haptic devices cannot provide.